1. Field of the Invention
This invention relates to a process and apparatus for servicing apparatus used in the processing of semiconductor wafers. More particularly, this invention relates to a process and apparatus which is useful in the cleaning of a reactor chamber used for the deposition of epitaxial silicon on a silicon wafer.
2. Description of the Related Art
In the deposition of an epitaxial layer of silicon on a silicon semiconductor wafer by chemical vapor deposition (CVD) in a vacuum deposition chamber, using chlorosilane gas, various chlorosilane polymer byproducts or residues form in the deposition chamber.
When the deposition chamber is subsequently opened to the atmosphere for servicing, moisture and/or oxygen-containing gases can enter the chamber and react with such chlorosilane polymeric residues to form chlorosiloxane polymers, which can result in the release of significant amounts of corrosive HCl gas and a powdery material which sometimes ignites.
Control, or preferably elimination, of such a reaction of moisture or oxygen with chlorosilane residues accumulated in a vacuum deposition chamber of semiconductor wafer processing apparatus is, therefore, important for safety, reliability, and particle defect reduction.
One previous approach to the solution of this problem has been to use exhaust systems to ventilate the area around the vacuum deposition chamber so that when the chamber was opened and exposed to moisture and/or oxygen-containing gases, the corrosive and inflammable gaseous byproducts, generated during such exposure, could be removed as they were formed.
While such an approach reduced at least some of the deleterious effects of such chlorosiloxane formation, it would be more desirable if the reaction itself of the chlorosilane with moisture and/or oxygen to form chlorosiloxane could be completely suppressed or eliminated.